This plastic mannequin head, which was found on the 6,277 metres below the surface of Japan's Sagami Bay is among nearly 2,000 examples of deep sea debris documented by an ocean research organization. And they're not even looking for it.

That’s just a few examples of the carelessly tossed trash fouling the ocean floor, according to a Japanese organization that is cataloging the astonishing amount of junk humans have dumped beneath the waves.

Launched this week by the Japan Agency for Marine-Earth Science and Technology, the Deep-Sea Debris Database combs three decades worth of photos and videos captured by their fleet of submarines off the archipelago’s coast.

“I want people to know that trash at sea not only floats ashore, but affects the sea at depths of 10,000 metres,” said the agency’s Hideaki Saito.

Among the refuse in the fully searchable database – which is available in English and Japanese – are a tire tube found 1,456 metres below the surface of Sagami Bay and an 18-litre metal can that settled in the Kumano Trough after a nearly 2,100-metre descent.

The database is just the most recent alarm to ring over the health of our oceans, even at their darkest depths. A study released in February outlined the “extraordinary” levels of toxicity in the Mariana Trench. Researchers said the levels of contamination found in creatures that dwell 10 kilometres below the surface were 50 times higher than crabs living in the Liaohe River, one of China’s most polluted waterways.

“The expanse of the deep sea infers that there are still large areas untouched by (human) activity,” the study’s authors wrote. “Although the intrinsic linkages between the deep sea and surface waters would suggest this inference is ill-conceived.”

Let’s have a look at some of the junk the JAMSTEC team stumbled across to help illustrate how “ill-conceived” that actually is.

JAMSTEC

A litany of plastic bags, aluminum cans and even a beach ball are strewn among the crabs and fishes more than 1,400 metres deep in Sagami Bay.

JAMSTEC

Several days after the first image was capture, an even more astonishing field of Sagami Bay plastic was spotted nearby.

JAMSTEC

In case you thought humans stopped polluting Sagami Bay in the 90s, this plastic doll was found in 2008.

JAMSTEC

One must admit that the ocean floor would be an unusual place for a fender bender. So how did a bumper reach the bottom off Sanriku?

JAMSTEC

Warning labels on batteries urge us to dispose of them properly. This is not an example of proper battery disposal.

We return to Sagami Bay, where this washing machine was spotted at a depth of 1,317 metres in 1997.

JAMSTEC

What appears to be a film reel rests at a depth of 597 metres in the Nankai Trough.

JAMSTEC

This unidentifiable metal equipment was discovered at a depth of 1,300 metres in Suruga Bay, though some creatures had taken to calling it home.

JAMSTEC

Whatever this is, it's quite large and it somehow ended up nearly 7,500 metres below the Sea of Japan's surface.

JAMSTEC

The Mariana Trench is the deepest part of the ocean, home to some of the world's most mysterious and unusual creatures. It also hosts this steel chain and its remarkably intact rope companion.